Method of preparing potable water

Abstract

A method of removing organic carbon and other contaminants from a water stream. The method comprises screening large solids from the stream. Pre-oxidation chemicals may then be added. A coagulant is fed into the stream. An activated carbon, preferably formed from lignite, is added by pumping a highly concentrated activated carbon slurry into the stream. The stream, including the activated carbon and coagulant, next flows into a clarifier, where the coagulant will flocculate and enmesh the activated carbon. The activated carbon adsorbs organic carbon and other contaminants, including bacteria, pharmacological agents, and hydrocarbons, as the stream flows through the clarifier. Eventually, the flocculate will agglomerate and settle out in the clarifier, where it, the enmeshed carbon, and the contaminants they contain may be removed. The stream's organic carbon content exiting the clarifier will be much reduced. Accordingly, less primary oxidizing agent will be needed to treat any remaining organic carbon.

Description

BACKGROUND OF THE INVENTION[0001]Field of the Invention: The invention relates to water treatment in general and treatment of drinking water in particular.[0002]Prior Art: Much drinking water comes from surface water sources, such as rivers, lakes, and artificial impoundments or reservoirs. Water from these sources has varying degrees of impurities that must be removed or treated before the water is safe to drink. One contaminant present in many surface water sources is organic matter. Sources of organic matter include decaying plants and animals, urea, fertilizer, and other materials commonly present in surface water. Organic material in water will support bacteria. The bacteria consume oxygen as they breakdown organic material. The bacterial consumption of oxygen is measured as BOD, or biological oxygen demand. It is a key metric in assessing and treating water that is to be rendered potable. BOD should be low before water is safe to drink or, in the case of wastewater, safe to di...

AI Technical Summary

Benefits of technology

The present invention relates to a method for easily suspending and restoring carbon particles in a slurry. The main advantage of this invention is that most carbon particles can be easily returned to suspension in the slurry by resuming agitation. The polyacrylamide polymers increase the viscosity of the slurry, which helps suspend carbon particles. However, if carbon particles fall out of suspension, they will not clump together, as they are still surrounded by the viscous media. The slurry can be formed off-site and transported to the injection site for stream 1 via container, even if the container lacks agitation. The carbon particles can be returned to suspension by subjecting the slurry to mild to moderate agitation. The use of activated carbon slurry simplifies the process of introducing activated carbon into a stream for treatment, as it can be easily pumped into the stream.

Problems solved by technology

One contaminant present in many surface water sources is organic matter.

However, treatment of water streams with chlorine can produce numerous chlorination disinfection by-products—many of which are undesirable.

Monitoring is required for many chlorination by-products, and excessive amounts will render water unsuitable for human consumption.

Geosmin and MIB have a very unpleasant, earthy odor.

When MIB and / or Geosmin is present in water, the taste and odor of the water can be compromised.

Other biological contaminants, such as Synura and other algae, can release chemicals that adversely effect the taste and odor of water.

Their presence can also compromise the taste and odor of water, in addition to posing a health risk if consumed.

Images